Key cutter



M r 1969 w. R. G. HAGGSTROM KEY CUTTER Sheet Wler 13.

Filed Aug. 25, 1961 March 4, 1969 R, G, HAGGsTm' 3,430,535

KEY CUTTER Filed Aug. 25. 1961 Sheet 2 of 5 T 3 203 225 I 2/0 4/ TE :1 E 75 79 KB f; 25 7/ 73 h -1 12' i lr g 24 2/ INVENTOR I "Qlfegii. ljfz sirom/ MarCh 1969 w. R. G. HAGGISTROM 3,430,535

KEY CUTTER File'd Aug. .25. 19s Sheet 5 of 5 March 4, 1969 w. R. G. HAGGSTROM 3,430,535

KEY CUTTER Sheet Filed Aug. 25, 1961 W INVENTOR alter E. .H sfrom flf ATTORNEY Mardl 1969 w. R. G. HAGGSTROM 3,

KEY CUTTER Filed Aug. 25, 1961 Sheet 5 of a T lt 16 I T1 12: 40 9! 36 224 INVENTOR I I I v va -J= HZ a 691 p92 is 1am I iZ-EATTOR Y United States Patent Oflice 3,430,535 Patented Mar. 4, 1969 3,430,535 KEY CUTTER Walter R. G. Haggstrom, Westminster, Mass., assignor to Independent Lock Company, Fitchburg, Mass, a corporation of Massachusetts Filed Aug. 25, 1961, Ser. No. 133,957

US. Cl. 90--13.05 Int. Cl. 1523c 3/28, 3/35; B2511 U02 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a key duplicating device, and more particularly to a copying device for cutting or bitting the blade portion of a key blank to form thereon a tumbler operating combination corresponding to the combination of any selected key. More particularly this invention relates to a key cutting device wherein a tumbler operating pattern formed on the blade portion of a selected key may be duplicated or reproduced on a selected key blank.

This invention is directed particularly to a key cutter or duplicator which is substantially automatic and foolproof in operation, whereby the same may be successfully operated by a person having no prior experience in the handling of key cutters. Moreover, the simplicity of operation of the machine is such as to render possible its use in a key vending device, whereby selection of or delivery of a key blank to be duplicated, as from or by a key blank vending machine or the like, and the introduction of the key blank, manually or automatically, into the key cutting machine will automatically result in cutting a perfect copy.

In its more specific phases, this invention relates to an automatic key cutter having a novel key and key blank clamp assembly whereby a cutting cycle is initiated automatically by proper insertion of the key and key blank into the clamp mechanism. Conversely, one of the features of this invention is the provision in the device of control means whereby no cutting can take place unless the key and key blank have been accurately and correctly positioned in the clamp provided therefor.

Still a further feature of the invention is the provision of an automatically actuated key clamp mechanism whereby a key and key blank may be freely inserted into seats or receptacles provided therefor (either manually or automatically) and which, when properly seated, will be firmly and fixedly clamped during the key cutting cycle of the device and released at the completion of such cycle.

Still a further feature of the invention lies in a novel key clamp which will fixedly clamp a blank and a patterned or cut key through the actuation of a single mechanism, notwithstanding possible thickness differentials existing between the key and the blank.

Further, this invention relates to a key duplicator wherein a key and key blank are fixed in position with respect to a movably mounted cutter and pattern follower unit which is driven automatically through a cycle whereby the pattern of the cut key is traced and the cutter unit guided in a manner to cut or mill away the key blank to correspond to the pattern of the cut key.

Still further, this invention relates in an embodiment thereof to a key cutter actuated through a cutting cycle by electrical circuitry which includes as a conductive portion thereof the key and the key blanks themselves when properly seated.

Accordingly, it is an object of this invention to provide a key cutting machine which is largely automatic in its operation. A further object of this invention is to provide a novel clamping and actuating mechanism for a key Cutting machine whereby proper insertion of a key and key blank into seats provided therefor completes the steps necessary for setting into motion the mechanism for reproducing on the blank the pattern formed on the key.

Still a further object of this invention is the provision of a key cutting device which eliminates the tedious and critical manual adjustment of the key and key blank with respect to the key clamp which was required in the use of key cutting devices heretofore known.

Still a further object of the invention is the provision of a novel key jig or clamp device.

Still a further object of this invention is an integrated key cutting apparatus which is simple to operate, dependable in performance and produces cut keys which reproduce within very close tolerances the dimensions of the pattern key.

Still a further and primary object of this invention is the production of a key "cutter which may be used in conjunction with a key vending device by persons unskilled in the art of locksmithing and unaccustomed to the operation of a key cutting machine and the requirements for accurate reproduction of cut keys.

Still a further object of this invention is the provision of a key clamp for holding a key and key blank, the jaws of which are actuated by a single shiftable actuator and which nonetheless may accommodate itself for simultaneously and accurately seating and holding a key and key blank of disparate thickness.

Still a further object of this invention is the provision of a key cutter and associated mechanism having the advantages heretofore and hereinafter set forth.

The improvements in the key cutting art provided by this invention may be best understood in conjunction with a brief discussion of key cutters heretofore known. The usual key cutter arrangement has heretofore comprised a cutter wheel and a follower or tracer member in fixed relation to each other. A shiftable carriage having spaced clamps for the key and key blank is also provided. The key and key blank must be carefully aligned in the clamps, and the latter closed while the key and key blank are maintained in the aforesaid aligned condition. The carriage normally is then manually shifted to direct the cutter against the length of the blade of the key blank while the follower rides over the bitted surface of the key to cause the blank to move relative to the cutter in the same manner that the key moves relative to the follower,

From the above rather general description of the usual key cutter arrangement, it will be readily recognized that if either the key or the key blank is even slightly misaligned within their respective clamps, the pattern of the key will not be properly reproduced on the blank. Similarly, unless the shifting of the carriage is carefully and uniformly carried out to assure cutting to a proper depth and thorough and complete scanning of the cut key, faithful reproduction of the key pattern on the blank will likewise not be attained. The aligning and shifting operations aforesaid are time consuming even for a skilled locksmith.

Of late there has been a tendency to provide key duplicating facilities at establishments other than purely locksmithing enterprises, service stations, hardware stores, super-markets and shoe shine parlors being examples.

'3 Such enterprises are normally staffed by clerks having little or no prior experience in the operation of a. key cutter. As a result, there is a relatively high incidence of improperly cut keys produced.

The improved cutter hereinafter described and claimed provides uniformly accurate key copies when used by an expert or by a person having no previous key cutting experience. In the hands of the expert the improved cutter is considerably faster to use than cutters heretofore known. Also, as previously indicated, a novice is able to use the device without previous experience, with the assurance that any key cut by the machine will duplicate exactly the pattern of the key to be copied since, unless the key and key blank are properly positoned within the machine, the assembly cannot be actuated or will not operate.

To attain these objects and such further objects as my appear herein or be hereinafter pointed out, reference is made to the accompanying drawings, forming a part hereof, in which:

FIGURE 1 is a perspective view of the general assembly in accordance with my invention;

FIGURE 2 is an enlarged sectoin taken on the line 2-2 of FIGURE 1;

FIGURE 3 is an enlarged front elevation;

FIGURE 4 is a fragmentary section taken on the line 4-4 of FIGURE 3;

FIGURE 5 is a fragmentary section taken on the line 5-5 of FIGURE 4;

FIGURE 6 is a fragmentary perspective view illustrating the relationship of the carriage to the drum for reciprocating the carriage;

FIGURE 7 is an enlarged fragmentary perspective View of the key seating means;

FIGURE 8 is a fragmentary perspective view of the key seating means showing the terminal connection;

FIGURE 9 is a fragmentary side elevation of the flexible drive connection;

FIGURE 10 is a section on the line 10-10 of FIG- URE 9;

FIGURE 11 is an enlarged perspective view of the key clamp assembly;

FIGURES 12 and 13 are enlarged fragmentary details showing the positions of the key hold down levers for clamping and releasing the key;

FIGURE 14 is a fragmentary section taken on the line 1414 of FIGURE 13;

FIGURE 15 is a wiring diagram of the electric circuit.

In accordance with the illustrated embodiment, there is shown in FIGURE 1 a console cabinet 10 in which is contained a key cutting device 11 in accordance with the invention. As may be seen from FIGURE 1, the console 10 is provided with slots 12, 13 in the front wall 14, which slots constitute the sole means of access necessary for operation of the key cutter 11 contained in the cabinet.

The key cutting device comprises a clamp or jig 15 for positioning and maintaining the key and key blank during the cutting operation, a follower and cutter assembly 16 for carrying out the actual milling or cutting operations, and a drive mechanism 17 for causing the cutting assembly 16 to move relatively to the clamp or jig 15 to effect the cutting or milling aforesaid.

As best seen in FIGURES 2 and 3, there is provided a support base 20 which is preferably fixed to a horizontal shelf (not shown) within console 10 (or to the top of a work surface). The jig or clamp 15 includes a vise block 21 fixed adjacent a forward edge 22 of the base 20. Formed in the block 21 are a pair of key seats 23, 24 for the key blank KB and the patterned or bitted key K.

As best seen in FIGURES 3, 5 and 11, the seats 23, 24 are square U-shaped in cross section and are provided with leaf spring members 25, 26, respectively, extending toward the guide walls 27, 23, respectively, from jaw members extending from inner walls 29, 30, respectively. The bottom or floor portions 31, 32 of the seats are (:0- planar and serve to adjust the key blank and key heightwise with respect to the cutter and follower, to be described hereafter.

Means 33, 34 are provided for seating the key and key blank against the bottom walls 31, 32. Such means include hold down levers 35, 36, pivotally connected by stub shafts 37, 38, to the vise block 21. Levers 35, 3d are provided adjacent their end portions 39, 49 with downwardly directed leaf spring members 41, 42. The hold down levers are normally maintained in the pivoted key seating position shown in FIGURE 12 by hold down support levers 43, 44, themselves pivotally mounted to block 21 by means of stub shafts 45, 46, rotatably carried by the block. Support levers 43, 44 are provided with finger portions 47, 43 which underlie and support offset extending arms 49, 56 of the hold down levers 35, 36, respectively (see FIGURE 7). Stub shafts 37, 38 are provided with pinion gears 51, 52. Similarly, stub shafts 45, 46 are provided with pinion gears 53, 54. A pair of rack members 55, 56 have their lower ends 57, 58 operatively connected to armatures 59, 60, respectively, which lie within solenoids -61, 62, respectively. The solenoids are fixed to the vise block and coil compression springs 63, 64 biased between the upper ends of the solenoids 61, 62, respectively, and collars 65, 66 secured to the racks 55, 56, respectively.

The rack members 55, 56 are toothed, rack 55 engaging gears 51, 53, and rack '56 engaging gears 52, 54. The toothed portions of racks 55, 55 are cut away at portions 550, 56a which lie adjacent gears 51, 52, in a manner whereby downward movement of a rack portion will not impart immediate movement to gears 51, 52.

From the above-described arrangement, it will be readily understood that the upward biasing influence of springs 63, 64 against collars 65, 66 maintain the racks 55, 56 in the up or raised position shown in FIGURE 12. The racks, in turn, by their engagement with gears 51, 53 and 52, 54 maintain the hold down levers 35, 36 in position whereby the spring members 41, 42 are disposed above seats 23, 24. Similarly, the ends 47, 48 of support levers 43, 44 are disposed beneath end portions 49, 56 of hold down levers 35, 36, thus preventing a lifting influence on the end parts from causing the hold down levers to pivot.

The hold down members 33, 34 and springs 41, 42 thereof thus far described serve temporarily to hold a key and key blank inserted in seats 23, 24, flat against bottom walls 31, 32. At the same time, springs 25, 26 hold the inserted key against side guide walls 27, 28. Before cutting of the key, the temporary restraint provided by the above-described key and key blank seating apparatus is relieved and the key and blank locked fixedly in the seats by clamping apparatus now to be described.

The permanent clamp apparatus assures that both the blank and the cut key will be locked in the vise during cutting, notwithstanding there may be differences in the thickness of the key and the key blank. The clamp apparatus includes jaws '71, 72 which are slidable toward and away from walls 27, 28, respectively. Spring means (not shown) connect the jaw members and tend to urge the inner ends 73, 74 of said members toward each other. A concentric cam member 75, having symmetrically shaped iobes, is disposed between the ends 73, 74. The cam member 75 is fixed to shaft 76 which is, in turn rotably mounted in bearing aperture 77 formed in clamp 21. The bearing aperture 77, as best seen in FIGURE 5, is formed to be longitudinally extended so as to permit a degree of movement of the shaft 76 longitudinally toward and away from the guide walls 27, 28. A locking lever 79 is fixed to shaft 76, the end 80 of the lever being connected by draw bar 81 to the armature 82 of solenoid As will be understood from the foregoing description, activation of the solenoid 83 will cause the armature 82 to enter said solenoid, shifting lever 79 clockwise, as shown in FIGURE 5, rotating shaft 76 and urging eccentric 75 against the ends 73, 74 of jaws 71, 72. The jaws 71, 72 will then shift outwardly toward guide faces or walls 27, 28, firmly clamping the key K in seat 24, and the key blank KB in seat 23. The clamp is selfequalizing in the event that the key and key blank are not of equal thickness by reason of the shiftable mounting 76 in bearing aperture 77.

For instance, if the key K is of greater thickness than keyblank KB, the rotation of cam 75 will force jaw 72 into contact with key K in advance of the jaw 71 contacting blank KB. As a result, further outward movement of jaw 72 will be prevented and further rotation of cam 75 will cause the cam and shaft 76 to move bodily toward blank KB until jaw 71 is forced into clamping engagement with such blank. The importance of the clamp to accommodate a key and blank of disparate thickness may be readily appreciated since even a slight movement of either member during the cutting operation will result in an improperly duplicated key.

Switching means are provided on the clamp member for initiating the key and key blank clamping operation. As the switching means which operate in conjunction with blank KB and key K are identical, there is shown in FIGURES 7 and 8 embodiments of the switching means for the key K, it being understood, however, that the switching means for the key blank and key are seriesconnected and that, therefore, activation of the circuit can be effected only if both the key and key blank switches are closed. Also, the parts of the corresponding key blank clamp switch will be referred by the same reference numerals as the key switch, with the addition of primed designations.

In the embodiment of FIGURE 7, hold down lever 36 is provided with a cross-bore 90 within which bore a pin 91 is shiftably received. The pin 91 is of a length to pro ject its outer end 92 a distance beyond the front or outerface 93 of the lever 36, a headed portion 94 being formed at the inner terminal end of the pin 91.

A pair of normally spaced resilient contact blades 95, 96 are mounted in an insulator block 97 fixed to the lever 36. The outer blade 95 bears against headed portion 94- of pin 91 and maintains the outer portion 92 thereof normally extended beyond the face 93 of the lever 36. The outer face 93 of lever 36 is aligned with the front face of the vise or clamp block 21. When a key is inserted into seat 24, a shoulder portion S thereof engages the end 92 of pin 91 and as the key is further inserted, shifts the pin inwardly, causing blade 95 to approach blade 96. The blades 95, 96 are spaced to be in contact when the shoulders S, S of the key K are in contact with the face 93 of lever 36, and the front face of vise 21, respectively. Thus, the circuit through contacts 95, 96 can be closed only if the key (or key blank) is inserted fully into the seat provided therefor in a manner to cause shoulders S and S to bear against or abut the seat adjacent portions of the clamp mechanism. The series wiring of the key and key blank switches assures that the clamp mechanism cannot be activated unless both key and key blank are properly inserted.

In connection with the embodiment of FIGURE 7, it

is to be noted that blade 95 provides a soft spring pressure, whereas the sideward pressure of Spring 26 and downward pressure of spring 42 are relatively great, thus assuring that the key will not, after being released by the operator, be forced backward by the pressure of blade 95.

In the embodiment of FIGURE 8, an insulating insert 100 is carried by lever 36. A conductive contact 101 is housed within the insert so as to present its outer face precisely flush with the face 93 of the lever 36, and the front face of vise block 21. In this embodiment, the key (or key blank) itself forms a component of the circuit which is completed when shoulder S touches contact 101, the vise 21 forming a ground and completing the circuit through the key.

In both switch embodiments, the leads a, 96a may be of flexible conductor material to permit the pivotal movement of the hold down lever aforesaid, but optionally and preferably, some form of sliding commutator contacts (not shown) are employed, which contacts may be of any known form suitable for electrically communieating two relatively movable parts.

The duplicating mechanism comprises a shiftable carriage 200 mounted for horizontal linear sliding movement toward and away from the clamp vise 21. A duplicator head or block 201 is mounted on the carriage to be shiftable vertically with respect to the carriage. The duplicator head includes a follower or tracer member 202 and a miller or cutter wheel 203. A drive motor M is operatively connected to drive the cutter wheel 203 and to power the carriage feed assembly 204, said assembly serving cyclically to shift the carriage toward and away from the clamped key and key blank, whereby the follower member 202 may scan the bitted surface of the key K, causing the block 201 carrying cutter wheel 203 to be raised or lowered in accordance with the hitting of key K, and thereby causing a hitting identical to that of key K to be cut or inscribed in the key blank KB.

The carriage 200 is mounted on horizontally disposed guide struts 205, 206, said carriage being provided with parallel bores 207, 208, suitable antifriction rollers (not shown) being disposed in said bores to permit the carriage to slide freely on struts 205, 206. The carirage 200 is provided with four spaced upstanding bars or posts 209, 210, 211, 212, which form guideway elements for duplicator head 201. The head 201 is provided with vertically disposed bores 209a, 210a, 211a, 212a, correspondingly spaced to receive the posts or bars 209, 210, 211, 212, respectively. Suitable antifriction bearing means (not shown), such as roller bearings, are interposed between the said posts and the bores to facilitate vertical shifting movement of the head 201 with respect to the carriage 200 Milling or cutting wheel 203 is carried by shaft 220, rotatably journalied in head 201, an arbor 221 being provided for removably locking the cutter 203 to shaft 220. A bracket 222 is secured to the front face 223 of duplicator head 201, a follower tracer cam 224 having an ex tended shank 225 being adjustably secured within slot 226 formed in said shank by locking screws 227. The tracer tip 228 of cam follower 224 is disposed in the same vertical plane as the cutting periphery 229 of wheel 203. Similarly, the tip 228 is adjusted by means of screws 227 to lie in the same horizontal plane as the lowest point of the periphery 229 of cutter 203.

Motor M is operatively connected to rotate shaft 22%? carrying cutter wheel 203 by articulated and extensible connector member 230. Connector 230 includes a first universal joint 231 at the end of shaft 220, a second universal joint 232 at the shaft 233 of the motor M and a telescopic drive shaft 230 which links universals 231 and 232. The drive shaft includes an outer shaft member 234 having an axial internal bore 235 and a pair of radially extending pins 236, 237 communicating with said bore. Inner shaft member 238 is secured to universal 231 and includes a pair of longitudinal slots 239, 240 slidably engaging pins 236, 237, respectively. Thus, the shaft 238 may slide telescopically within bore 235 of member 234, the pins and slots above-described providing a torque transmitting connection between the inner and outer shaft members. It will be recognized that the extensible drive member 230 above-described will function to rotate cutter 203 and will, at the same time, permit the block 201 to be moved horizontally and vertically with respect to motor M.

The carriage 200 is cyclically shiftable toward and away from clamp member 21 by cam drive means 204 7 which, like cutter 203, is driven \by motor M. A cylindrical drum 250 is mounted with its axis horizontally disposed beneath the carriage 200, a concave portion 200a being formed beneath the carriage to provide clearance.

The drum 250 is secured to drum drive shaft member 251, which is journalled in standards 252, 253 provided with suitable bearings for said shaft 251. The shaft 251 is driven at a very slow speed by the output 254a of worm reduction gear assembly 255, the input 254k to the worm assembly being driven by belt 256, linking pulley 257 attached to shaft 233 of motor M and pulley 258 secured to said input shaft 25411.

The drum 250 is provided with an endless helical cam groove 260 on its outer face, said groove providing a path around the entire drum face and including longitudinally extending components. A follower roller 261 is rotatably carried by stub shaft 262, which depends from the underside of carriage 200. The roller 261 rides in groove 260 and when the drum 250- is rotated through a complete revolution, the carriage 200, by the driving engagement of the roller in the groove, is cyclically shifted forwardly toward the clamp member and withdrawn to the initial position shown in FIGURE 2.

In FIGURE there is schematically shown a wiring diagram providing for automatic operation of the key cutting device whereby cutting of a key blank is effected responsive to proper insertion of a bitted key and a key blank. It should be understood that this diagram is merely illustrative of a suitable circuit and that other circuitry may, in the light of the preceding description, be devised by those skilled in the art.

Main input lines 300, 301 are connected to a suitable power source, preferably of alternating current (A.C.). Optionally, an on-off switch (not shown) may be employed in one or both of the input lines, or the device may be powerized by activation of a suitable coin controlled switoh (not shown) which switch may, for instance, be associated with a key blank vending machine. A step down transformer T has its primary coil P connected to the main power lines 300, 301. One side of the transformer secondary coil S is connected by lead 302 to coil 304 of main power relay 305. The other side of secondary S is connected to lead 96a of blade 96' of the key blank operated switch. Lead 95a of blade 95 is connected to input contact terminal 307 of clamp relay 308. The other contact terminal 309 of relay 308 is connected to lead 95a of blade 95 of the key control switch. Lead 96a of said switch is, in turn, connected to the other side of coil 304 of main power relay 305. Relay 308 is of the normally closed type, terminals 307, 309' being normally connected by armature actuated element 311.

Main power relay 305 is of the single pole, double throw type and the armature actuated element 312 thereof is normally mechanically set to the position shown in FIGURE 15 by the return travel of carriage 200 to the ready position shown in FIGURE 2. The element 312 may be positioned either to complete the circuit between switch terminals 313, 314 or between terminals 315, 316, the normal position in the inactive condition of the machine being to connect the latter pair of terminals.

When a key blank KB and a key K are properly inserted in seats 23 and 24, respectively, the coil 304 of main power relay 305 is connected to the output leads 302, 96a of secondary S of step down transformer T through the now-closed blades 95, 96, 95, 96- and shorted terminals 307, 309. The activation of coil 304 causes the armature controlled element 312 to shift from the position of FIGURE 15 and to complete the circuit between relay terminals 313, 314. The shifting aforesaid of main power relay 305 connects power line 301 to switch controlled line 301a, thus activating solenoids 61, 62 and 83 and motor M, and deactivating solenoid 83a. Also, coil 320 of relay 308, the terminals 321, 322 of which are connected to lines 301, 301a, respectively, is energized, thus breaking the circuit between relay terminals 307, 309.

Key blank KB has been held against walls 27, 31 of seat 23 by the combined action of springs 25 and 41. Similarly, key K has been held against walls 28, 3-2 of seat 24- by the combined action of springs 26 and 42. Upon energization of solenoids 61, 62, the rack members 55, 56, respectively, thereof are gradually shifted downwardly against the resisting pressure of springs 63, 64, respectively. The initial downward movement of the racks through their driving connection with pinion gears 53 and 54 causes support levers 43, 44 to be pivoted outwardly to move portions 47, 48 of said levers clear of portions 49, 50 of the hold down levers 35, 36, respectively. (The initial shifting aforesaid of lever 44 is shown in dot and dash lines, FIGURE 12.) The levers 35, 36 do not pivot immediately upon downward shifting of the racks 55, 56 by reason of the cut away portions a, 56a of said racks adjacent gears 51, 52, respectively, whereby no pivotal movement is imparted to the hold down levers until the support levers have been cleared from contact therewith.

As the racks 55, 56 continue to descend, levers 35, 36 are pivoted clear of the key blank and key, respectively, thus exposing the uppermost edges of the key and blank to the tracing and cutting mechanism. (See FIGURE 13 in connection with the position of arm 36.)

Simultaneously with the pivoting of levers 35, 36 aforesaid, the activation of solenoid 83 causes armature 82 and draw bar 81 to be shifted, urging holding clamp lever 79 to the right, as shown in FIGURE 4. This imparts a clockwise rotary movement to shaft 76 and eccentric 75, thereby forcing jaws 71 and 72 outwardly into firm key and blank clamping position. As previously described, the jaws will provide strong clamping action against the key and key blank, even if the latter are not of equal thickness.

As shown in the schematic circuit diagram, FIGURE 15, relay 308 opens the transformer secondary circuit when the main power relay 305 is energized. The relay 308 may be dispensed with when the switching embodiment of FIGURE 7 is utilized since the upward pivoting movement of arm 36 will swing tip 92 of plunger 91 clear of shoulder S, thus automatically breaking the transformer circuit in such embodiment.

Simultaneously with the energization of solenoid 61, 62 and 83, motor M is activated. Motor M in addition to driving cutter wheel 203, operates through the medium of belt 256 and worm assembly 255 to rotate shaft 251 connected to the drum 250. One rotation of drum 250 completes the key cutting and withdrawing cycle in the illustrated embodiment and, accordingly, the worm gear and belt drive speed reduction must be calculated to rotate the drum once in about 10 seconds.

As the drum rotates, the carriage 200 is urged forwardly or toward the clamped key and key blank. The tracer or follower member 224 will be impinged against the bitted upper face F of key K, with the lower edge 228 of said member 224 riding intimately over this face. As the carriage advances toward the clamp, the duplicator head 201 is raised and lowered by the action of the tracer 224 following the contours of bitted face F of the key. The cutter wheel cuts or mills the key blank KB in accordance with the raising and lowering of the head 201, the weight of head 201 being preferably very considerable, to provide the force for urging the cutter wheel 203 against the blank KB. Optionally, spring means may be employed instead of, or in conjunction with, a massive head element 201, to provide the required key cutting force.

Upon rotation of the drum 250, the cutter wheel and tracer are at their forwardmost point, the second 180 rotation of said drum serving to withdraw the carriage, and hence the head. Thus, on the return stroke of the carriage, further cutting of the blank may be effected if, for instance, a deep cut in the key bitting was not fully duplicated on the blank KB on the initial or approach stroke.

At the rearwardmost point of carriage 200 main power relay 305 is reset mechanically by contact with the car riage to the position shown in FIGURE 2, thereby breaking the circuit to motor M, and solenoids 6.1, 62 and 83. Simultaneously, solenoid 83a is powerized, thereby serving to shift draw bar 81a to the left, as seen in FIGURE 4, causing clamp arm 79 to move counterclockwise, releasing the jaws 71, 72 from clamping engagement, respectively, with the key blank KB and key K.

When solenoids 61, 62 are de-energized, the hold down lever 35, 36 return to the position illustrated in FIGURE 3 under the influence of return springs 63, 64. The key K and the cut key blank KB may then be removed and used, it being desirable in the case of the newly cut blank to scrape or wipe the newly bitted edge before use, to remove metallic burrs or chips which may cling to said edge.

From the preceding description it will be appreciated that the described key cutting device is entirely automatic in its operation, the sole manual steps required being the insertion into seats provided therefor of a cut key and a key blank. By reason of the novel actuator arrangement which predicates the initiation of a cutting cycle on the proper insertion of the key and key blank, it is impossible to ruin or improperly cut a key blank due to faulty positioning in the cutter.

The device is extremely safe to operate since the operator is not exposed to the moving cutter wheel.

Due to the ease with which the device may be operated even by one with no prior key cutting experience, the unit is ideally suited for use in conjunction with a key blank vending device in locations where key cutting is performed by clerks or others unskilled in the locksmithing arts, or in any busy locksmithin g establishments wherein time is of the essence.

The novel clamp arrangement described herein permits a key and key blank of disparate thickness to be out without the necessity of performing special adjustments. Also, it is possible, by reason, inter alia, of said novel clamping arrangement, to out two blanks at one time by inserting the blanks side by side on the blank seat member, for such operation certain minor adjustments Within the knowledge of the skilled worker being desirably incorporated.

Other objects and advantages of the disclosed device will be apparent in the light of the preceding description and, accordingly, this invention is to be broadly interpreted within the scope of the appended claims.

Having thus described the invention and illustrated its use, what is claimed as new and is desired to be secured by Letters Patent is:

1. A key cutter device for duplicating a key having transverse shoulder portions comprising a clamp member arranged to hold a key and a key blank, abutment portions on said clamp against which said shoulder of said key and blank, respectively, may be shifted for longitudinal positioning of the latter, a tracer and cutter .assembly cyciically movable into operative association with said key and blank, respectively, and a series connected actuator circuit arranged upon closing, to initiate said operative cycle, said circuit including as conductive portions thereof a contact in each said abutment portion said key and said key blank.

2. A cutter device in accordance with claim 1 wherein said contacts are disposed in the path of movement of the transverse shoulder portions of said key and key blank, respectively.

3. A cutter device in accordance with claim 2 wherein said abutment portions are pivotally mounted on said clamp means and are arranged to be pivoted out of engagement with said shoulder portions responsive to the initiation of said cutting cycle.

4. In a key cutting device including means for shifting a coordinated key tracer and key cutter in guided relationship to a shouldered key and key blank, respectively, clamp means for positioning and holding said key and key blank comprising spaced seats for said key and key blank, a temporary hold down member disposed adjacent each said seat in key depressing relationship thereto, means for shifting said hold down members clear of said seats in advance of the start of a cutting cycle, contact means on each said hold down member electrically isolated from said seats and located to engage a leading shoulder portion of a properly inserted key and key blank in the seat adjacent position of said members, and a series connected actuating circuit for initiating said cutting cycle including as conductive portions thereof said contact means and said key and key blank.

References Cited UNITED STATES PATENTS 2,645,978 7/1953 Sejarto et al 13.05 2,704,964 3/1955 Stolove 90-13.05 1,549,912 8/1925 Ebel 269-196 2,954,713 10/1960 Gaubert 269-196 1,081,471 12/1913 Tucker 90-1305 1,081,472 12/1913 Tucker 90-13.05 2,148,668 2/1939 Yoskowiz et al 9013.05

GERALD A. DOST, Primary Examiner.

US. Cl. X.R. 

